A magnetic sensor designed to sense a magnetic field in three orthogonal directions would typically require a sensor axis mounted perpendicular to a printed wire board (PWB), a printed circuit board (PCB), or other assembly used for mounting electronic components. However, this mounting arrangement causes the magnetic sensor to have a height that is usually greater than other devices mounted on the PCB. As a result, the height of the magnetic sensor may be a determining factor of the height of any electronic device that includes the sensor.
For example, some cellular telephones have magnetic sensors. Over time cellular telephones have decreased in size due to consumer demand for smaller electronic devices. The demand for even smaller cellular telephones makes the height of the magnetic sensor a potential design issue. The height of the magnetic sensor may become a design issue in other applications as well. Further, the height of the magnetic sensor may limit the placement of the sensor on a PCB.
Currently, the typical height of a magnetic sensor with respect to the PCB is approximately 5 mm. The input and output signals of the magnetic sensor are connectable via connection pads that are typically located in various locations around the magnetic sensor die or grouped by function. For example, a magnetic sensor may include connection pads for power (Vcc), ground (GND), an offset strap (OFF+, OFF−), a set/reset strap (S/R+, S/R−), and differential voltage output signals (OUT+, OUT−). The offset strap and the set/reset strap features of the magnetic sensor allow for incident field adjustment and magnetic domain alignment. FIG. 2 depicts one example of a typical pad layout for a magnetic sensor die.
It would be beneficial to package a magnetic sensor in a manner that minimizes the height of the sensor when mounted perpendicular to a PCB. However, any packaging method used to reduce height should also be cost effective.